Rebar spacer and method

ABSTRACT

A device for supporting reinforcing bars within a form for a concrete wall having transverse form ties includes a non-metal body, configured to attach to a form tie in a fixed orientation. At least one aperture is disposed in the body, and is configured to receive an elongate reinforcing bar, so as to substantially fix the position of the reinforcing bar with respect to the form tie.

BACKGROUND

1. Field of the Invention

The present invention relates to devices for supporting and securingreinforcing bars for concrete construction. More specifically, thepresent invention relates to a device and method for supporting andsecuring rebar upon a form tie within a wall form.

2. Related Art

Reinforced concrete is one of the most common and time-tested materialsin modern building construction. The placement of ductile steelreinforcing bars (“rebar”) within a concrete mass gives the resultingstructure the combined benefits of concrete's high compressive strengthand steel's high tensile strength and ductility. Additionally,cast-in-place concrete can be formed into almost any shape, allowing thecreation of beams, columns, arches, and other shapes in almost anydesired form.

It is well known that the strength and suitability of a reinforcedconcrete structure depends in part upon the quantity and location of thereinforcing steel. Considerable effort is expended in the design ofreinforced concrete structures to determine and specify the optimumamount and location of rebar. Consequently, one persistent challenge inthe subsequent construction of the structure is the proper placement ofmetal reinforcement within the concrete forms and keeping thereinforcement properly aligned (so as to provide adequate and consistentreinforcement) and with proper clearance from outer surfaces of thefinished structure (so as to protect the reinforcement from exposure tothe environment). If the steel is not placed according to the design,the resulting structure may not have the desired structuralcharacteristics, and/or may be subject to premature degradation fromenvironmental factors and age.

Rebar ties, chairs, and supports of various designs have been producedto help guide the placement of metal reinforcement. Unfortunately,forces created by the flow of wet concrete during placement can shiftand move rebar from its intended position even when rebar fixing deviceare used properly, and this can easily go undetected by workers, even ifthey are paying close attention. Furthermore, many devices forsupporting and securing rebar are inadequate for their purpose, eitherbecause of design aspects or difficulty of use. Some of these devicesrequire significant skill and care by their user to avoid improper orinadequate rebar placement.

Unfortunately, in the construction industry, economic pressuresconstantly work against the effort to apply proper skill and attentionto a given job. Placing additional chairs and ties within a form inorder to better secure the rebar in the proper place takes time andmoney. Since the position of rebar within a concrete structure isgenerally not visible after the concrete is placed, shoddy work caneasily go undetected during construction, and will generally not benoticed soon afterward except in extreme cases. Such flaws arefrequently only discoverable many years after construction, whenwarranties have expired and there is little chance of holding thebuilder accountable. Furthermore, low wage, low skill laborers (as arefrequently employed in the construction industry) may not possess theskill, knowledge or care needed to properly use devices that do exist tohelp with rebar placement, especially where such devices are cumbersomeor difficult to use.

SUMMARY OF THE INVENTION

It has been recognized that it would be desirable to have an apparatusand method for placing rebar within concrete forms that encouragesproper placement of the rebar and helps secure it better.

It has also be recognized that it would be desirable to have anapparatus and method for encouraging proper rebar placement that isinexpensive and simple to use.

In accordance with one embodiment thereof, the invention provides adevice for supporting reinforcing bars within a form for a concrete wallhaving transverse form ties. The device includes a non-metal body,configured to attach to a form tie in a fixed orientation. The bodyincludes at least one aperture, configured to receive an elongatereinforcing bar, so as to substantially fix the position of thereinforcing bar with respect to the form tie.

In accordance with another embodiment thereof, the invention provides aconcrete form system, comprising a wall form having transverse ties, anda non-metal rebar spacer, attached to a transverse tie in a fixedorientation within the wall form. The rebar spacer has at least oneaperture, configured to receive an elongate reinforcing bar, and tosubstantially fix the position of the reinforcing bar with respect tothe form tie.

In accordance with another aspect thereof, the invention provides amethod for supporting horizontal reinforcement within a concrete wallform. The method includes the steps of connecting a form tie betweenopposing vertical walls of the wall form, attaching a non-metal rebarspacer to the form tie between the form walls in a fixed orientation,and transversely inserting an elongate reinforcing bar into at least oneaperture disposed in the rebar spacer, so as to substantially fix theposition of the reinforcing bar with respect to the form tie.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional features and advantages of the invention will be apparentfrom the detailed description which follows, taken in conjunction withthe accompanying drawings, which together illustrate, by way of example,features of the invention, and wherein:

FIG. 1 provides a front view of one embodiment of a rebar spacer

FIG. 2 is a side, cross-sectional view of a concrete wall form, showingthe rebar spacer of FIG. 1 attached to a bar-type form tie;

FIG. 3 is a top view of the rebar spacer of FIG. 1;

FIG. 4 is a partial side, cross-sectional view of the rebar spacer ofFIG. 1.

FIG. 5 is a side, cross-sectional view of a concrete wall form, showinganother embodiment of a rebar spacer attached to a wire-type form tie;

FIG. 6 is a side, cross-sectional view of the rebar spacer of FIG. 5;

FIG. 7 is a front view of an embodiment of a rebar spacer configured tosupport rebar both above and below a form tie; and

FIG. 8 is a front view of an embodiment of a rebar spacer having abranched configuration.

DETAILED DESCRIPTION

A front view of one embodiment of a rebar spacer 10 in accordance withthe present invention is provided in FIG. 1, and a top view of the sameis shown in FIG. 3. Shown in FIG. 2 is a cross-sectional view ofopposing concrete forms 12 with a flat bar-type form tie 14 extendingtherebetween, and a rebar spacer disposed upon it. One piece of rebar 16is shown in cross-section, disposed in one of the top slots 18 of therebar spacer.

The rebar spacer 10 generally comprises a flat body 20 of non-metalmaterial with a variety of openings formed in it. In the embodiment ofFIG. 1, the top of the body includes several rebar apertures 18 that areopen rounded slots designed to receive and support rebar 16 (shown inhidden lines in cross-section in FIG. 1) that is oriented substantiallytransverse to the body of the rebar spacer. Other openings 22 are alsoformed in the body. These openings perform several functions. They allowliquid concrete to flow through the body, so that the rebar spacer doesnot hinder concrete placement, and also operate to provide a mechanicalinterconnection with the concrete that helps to anchor the rebar spacerand the form tie within the wall when the concrete has cured.Additionally, these openings reduce the total quantity and weight ofmaterial in the rebar spacer, which can help reduce manufacturing andshipping costs.

The rebar slots or apertures 18 are generally U-shaped, and have a totalwidth or maximum diameter that is large enough to accommodate rebar upto a certain intended size, taking into account the surface deformationsof the bar. The upper opening or mouth 24 of the slots include lips 26that protrude inwardly on each side of the opening. These lips arecloser together than the minimum diameter of the bar 16 for which theparticular slot is intended, so that a user is required to press the barinto the slot, after which the lips hold the bar in the slot in a pressfit. This helps prevent the bar form unintentionally coming out of theslot during placement of other rebar, or during placement of theconcrete in the form.

The lips 26 of the rebar apertures 18 also allow the rebar spacer 10 tosupport rebar 16 that is inserted from below. As shown in FIG. 2, therebar spacer can be attached to the form tie 14 in an invertedorientation (shown in dashed lines 28), so as to extend down form theform tie, to support and hold rebar that is below the form tie. The lipsof the rebar apertures allow the rebar, so long as it is of sufficientsize, to be inserted upward and held in the rebar aperture. This featureof the rebar spacer allows great flexibility of use, allowing the rebarspacer to support rebar above or below a form tie.

The rebar slots or apertures 18 can be of a variety of sizes, so as toaccommodate rebar of different sizes. For example, different rebarspacers can be configured for supporting #4 bars (i.e. ½″ diameter), #5bars ( 5/8″ diameter), etc., for all of the different standard rebarsizes, depending upon the size to be used in a given location. Thus,where several different sizes of rebar are to be used in a givenproject, rebar spacers configured for each size of rebar can beprovided. Alternatively, a single rebar spacer can include apertures ofdifferent sizes. For example, as shown in FIG. 2, the rebar spacer 10can include one or more apertures 18 a configured to receive a bar ofone size (e.g. a #4 bar), and one or more other apertures 18 bconfigured to receive and hold a bar of a different size (e.g. a #5bar). Additionally, it will be apparent that rebar of a smaller size canalways be supported in a larger slot when the rebar spacer is in theupright orientation, though such a use may not provide quite as tight afit. Nevertheless, where a wall includes both #4 and #5 bars, forexample, a rebar spacer that is configured with apertures sized tosupport #5 bars can be used throughout.

The bottom region 29 of the body 20 includes two open elongate slots 30that are configured to fit over the flat bar-type concrete form tie 14and allow the bottom of the device to be attached thereto. The slots aredisposed so as to provide a center tab region 32 and two outer tabregions 34. As shown in FIG. 2, the spacer body is attached to the formtie by deflecting the center tab region out of the plane of the body inone direction, while the two outer tab regions are deflected out of theplane of the body in the opposite direction. The body is then presseddown over the top edge 36 of the form tie, so that the center tab is onone side of the bar, while the outer tab regions are on the other sideof the flat bar.

A pair of deformable locking buttons 38 protrude from the plane of thebody 20 upon one side of each of the outer tab regions 34. A sidecross-sectional view of one of these buttons is shown in FIG. 4. Thelocking buttons comprise a pair of opposing tabs 40 with oppositelyoriented wedge-shaped lips 42 disposed on their extreme ends. The wedgeshape of the lips causes the tabs to deflect toward each other when thebutton is pushed into a slot 44 on the form tie 14. Once the tabs arepushed sufficiently far into the slot that the wedges emerge upon theother side of the bar, the tabs snap back into position, and the wedgeslock the button in place in the slot, and thus hold the rebar spacer tothe form tie.

The locking buttons 38 have an elongate shape that matches the shape ofthe slots 44 on the form tie, and thus helps to fix the orientation ofthe body 20 of the rebar spacer 10 upon the form tie 14. That is, theelongate shape resists rotation of the rebar spacer relative to the formtie, in addition to simply supporting the form tie. Additionally,because there are two locking buttons that are spaced a distance apart,this provides additional stability to the position of the rebar spacerwhen attached to the form tie. With the locking buttons press-fit intothe slots on the form tie, the rebar spacer is thus attached to the formtie in a substantially fixed orientation.

Naturally, the size of the rebar spacer 10 will vary depending uponvarious factors, including the size of the wall and the size (diameter)of the rebar it is designed to support. In the embodiment shown in FIGS.1 and 2, the device is designed to support ½″ diameter (#4) bars, and isapproximately 5.5 inches long, 2.5 inches high, and 3/16 inches thick.Other sizes and configurations are also possible. For example, the rebarspacer can be configured to support and hold various numbers of bars inalmost any desired arrangement, and the height of the spacer—and hencethe distance from the form tie at which the bars are held—can vary asdesired.

Shown in FIG. 5 is a front view of another embodiment of a rebar spacer50 configured to mount upon a wire-type form tie 52, rather than a flatbar-type form tie. A side, cross-sectional view of this embodiment isprovided in FIG. 6. This embodiment is much like the above-describedembodiment, with slots 54 in the top for supporting rebar 16, and otherapertures 56 in the body for allowing flow of wet concrete, etc.However, on the bottom edge 62, rather than open slots for sliding overan edge of a flat bar, this embodiment includes a pair of gripping feet58 for gripping the wire-type form tie 52.

Wire-type form ties are widely used, especially in commercialconstruction. These ties have a generally circular cross-section.However, as seen in FIG. 6, each tie includes a region 60 that ispartially flattened (i.e. a region not having a circular cross-section)toward each end of the tie. This flattened region provides a structuraldiscontinuity that allows the tie to be twisted and broken off at thatpoint after the concrete has at least partially cured and the form wallshave been removed. The gripping feet 58 of the embodiment of FIGS. 5-6extend along a portion of the bottom edge 62 of each lateral side of therebar spacer 50, and are configured to press onto and resiliently gripthe flattened region of the wire tie to support the rebar spacer.

As shown in the side, cross-sectional view of FIG. 6, the gripping feet58 include resilient forward and rearward portions 64, 66, that areconfigured to wrap around the flattened region 60 the form tie 52. Theopening 68 between the forward and rearward portions is smaller than thecorresponding dimension of the wire tie, so that the gripping feet mustbe pressed onto the wire in a press fit. Additionally, the interiorregion between the forward and rearward portions of the gripping feetincludes at least one flattened or faceted inner surface 70 that isconfigured to mate with a flat surface 72 of the flattened region of theform tie, so as to fix the orientation of the rebar spacer 50 withrespect to the form tie. That is, when the gripping feet are pressedonto the flattened region of the form tie, their resilient nature holdsthe flat surface of the gripping feet against the flat surface of theform tie, so that rotation of the rebar spacer upon the form tie isprevented. With two gripping feet spaced apart and the gripping feetincluding flattened or faceted surfaces, this embodiment of the rebarspacer thus also effectively attaches to the wire-type form tie in asubstantially fixed orientation.

Rebar spacers in a variety of other configurations can also be made inaccordance with the present invention. It was noted above that a rebarspacer such as that shown in FIG. 1 can be attached to a form tie in anupright orientation, so as to support rebar above the form tie, or canbe attached in a downward orientation, so as to hold rebar below theform tie. As another embodiment, shown in FIG. 7, a rebar spacer 80according to the present invention can be configured to support rebar 16both above and below a form tie. As shown, this embodiment includes alower portion 82 that is effectively an extension of the center tab 84of the rebar spacer. Both the lower portion and the upper portion 86include rebar apertures 88, the resilient lips 90 of the lower aperturesoperating to hold the rebar therein in the manner discussed above.

Other configurations are also possible. For example, as shown in FIG. 8,a rebar spacer 100 according to the present invention can be providedwith a branched configuration. In this embodiment, the lower portion 102of the rebar spacer is configured to attach to the form tie 104 in themanner described above. However, the upper portion 106 of the rebarspacer includes a first branch 108 and a second branch 110, each branchextending toward opposing side walls 112 of the form. Each branchincludes one or more rebar apertures 114, and operates to hold rebarnear to the opposing sides of the form. The branched configuration canbe used in situations where two layers of rebar on opposing sides of awall are desired. It will be apparent that the geometry and dimensionsof the branched rebar spacer can be selected to correspond to the totalthickness of the wall, so that neither the rebar nor the rebar spaceritself is placed too close to the outer surface of the finishedconcrete.

Rebar spacers according to the present invention can be made of avariety of materials, including polymers such as polypropylene,polyethylene, nylon, etc. The body of the spacer can be injectionmolded, machined, or formed in any other manner that is suitable for thetype of material. The use of non-metal materials helps prevent corrosionthat can degrade a concrete structure. As is well known, corrosion ofmetal reinforcement within a concrete mass not only gradually destroysthe reinforcing properties of the rebar, but also cracks and breaks upthe concrete because of the very high expansive forces created by thecorrosion process. Thus, if the rebar spacer were of a metal material,because it is in contact with the form tie and the metal rebar,corrosion of the exposed form tie end could result in corrosion of therebar spacer and the rebar through cathodic action, and thence of anyother electrically conductive material in contact therewith.

It is also desirable that the rebar spacer be somewhat flexible, thoughsuitable materials can have a wide range of flexibility. In order to fitover a bar-type form tie, as shown in FIG. 2, where the body of thespacer is substantially planar, it must be able to flex to allow thecenter tab and outward portions to slide over opposing sides of the formtie. Additionally, a certain degree of flexibility and resilience areneeded to allow the resilient lips of the rebar apertures to effectivelyreceive and hold the rebar therein, and some flexibility and resilienceare needed for the locking buttons and gripping feet.

At the same time, a large degree of flexibility is not necessarilyrequired. For example, for an embodiment like that of FIG. 1, the bodyof the rebar spacer need not be planar, but can be molded or otherwiseformed in a non-planar configuration that is adapted to slide over theform tie with portions abutting opposing sides of the form. Such aconfiguration can be of a more rigid material than may be desired forthe embodiment of FIGS. 1-2. Those skilled in the art will recognizethat the polymer materials mentioned above, and others not mentioned,can be adapted to provide the needed flexibility for the variousembodiments disclosed herein and modifications of them.

While a variety of configurations for the rebar spacer have been shownand described, it will be apparent that other configurations andcombinations of elements shown can also be provided. For example, any ofthe various rebar spacer embodiments shown herein can include grippingfeet for use with wire-type form ties, or locking buttons for attachmentto bar-type form ties. Rebar apertures of different sizes and indifferent positions can also be provided, and any number of rebarapertures can be included on a single rebar spacer, though practicallimitations of space and proper rebar spacing will likely affect thenumber and position of the apertures. Additionally, differentcombinations and arrangements of branches, etc. can also be used.

In its various embodiments, the invention provides a simple andinexpensive system and method for assisting accurate and consistentplacement of rebar in a concrete form. The rebar spacer helps ensureproper alignment of rebar in spite of worker inexperience orcarelessness, and helps prevent displacement of the rebar duringplacement of concrete. Additionally, because the device is simple,inexpensive, and easy to use, its use will not add significantly to thecost of construction.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

1. A device for supporting reinforcing bars within a form for a concretewall having transverse form ties, comprising: a non-metal body,configured to attach to a form tie in a fixed orientation; and at leastone aperture, disposed in the body, configured to receive an elongatereinforcing bar, so as to substantially fix the position of thereinforcing bar with respect to the form tie.
 2. A device in accordancewith claim 1, wherein the body is of a polymer material.
 3. A device inaccordance with claim 1, wherein the at least one aperture comprises aplurality of apertures.
 4. A device in accordance with claim 3, whereinthe plurality of apertures have varying diameters, so that the body isable to receive and hold rebar of varying diameters.
 5. A device inaccordance with claim 1, wherein the at least one aperture includes aresilient lip, configured to receive and hold rebar therein in a pressfit.
 6. A device in accordance with claim 1, wherein the body includesat least one aperture for allowing a flow of wet concrete therethrough.7. A device in accordance with claim 1, wherein the body includes anaperture disposed above the form tie.
 8. A device in accordance withclaim 1, wherein the body has a branched configuration, providingapertures for receiving reinforcing bars on more than one branch.
 9. Adevice in accordance with claim 1, wherein the body includes an aperturedisposed below the form tie.
 10. A device in accordance with claim 1,wherein the body is configured to attach to a form tie selected from thegroup consisting of bar-type form ties and wire-type form ties.
 11. Adevice in accordance with claim 1, wherein the at least one aperture isconfigured to support rebar that is oriented substantially transverse tothe body.
 12. A concrete form system, comprising: a wall form havingopposing form walls; a transverse form tie, interconnecting the formwalls; and a non-metal rebar spacer, attached to a form tie in a fixedorientation, the rebar spacer having at least one aperture, configuredto receive an elongate reinforcing bar, and to substantially fix theposition of the reinforcing bar with respect to the form tie.
 13. Asystem in accordance with claim 12, wherein the form tie is selectedfrom the group consisting of a bar-type form tie and a wire-type formtie.
 14. A system in accordance with claim 12, wherein the rebar spacerincludes a plurality of apertures.
 15. A system in accordance with claim14, wherein the plurality of apertures have varying diameters, so as tobe able to receive and hold rebar of varying diameters.
 16. A system inaccordance with claim 12, wherein the at least one aperture includes aresilient lip, configured to receive and hold rebar therein in a pressfit.
 17. A system in accordance with claim 12, wherein the rebar spaceris of a polymer material.
 18. A method for supporting horizontalreinforcement within a concrete wall form, comprising the steps of:connecting a form tie between opposing vertical walls of the wall form;attaching a non-metal rebar spacer to the form tie between the formwalls in a fixed orientation; and transversely inserting an elongatereinforcing bar into at least one aperture disposed in the rebar spacer,so as to substantially fix the position of the reinforcing bar withrespect to the form tie.
 19. A method in accordance with claim 18,wherein the step of transversely inserting the elongate reinforcing barinto the at least one aperture comprises inserting the reinforcing barpast a resilient lip of the at least one aperture, so as to place thebar therein in a press fit.
 20. A method in accordance with claim 18,wherein the step of transversely inserting the elongate reinforcing barinto the at least one aperture comprises inserting the reinforcing barinto an aperture that is disposed below the form tie.